Valve seat ring for the fastening in cylinder heads of internal combustion engines

ABSTRACT

A valve seat ring to be fastened in cylinder heads of internal combustion engines which includes a self-tapping thread by means of which the valve seat ring is secured in the material of the cylinder head.

United States Patent [1 1 Roll [ VALVE SEAT RING FOR THE FASTENING IN CYLINDER HEADS OF INTERNAL COMBUSTION ENGINES [75] Inventor: Walter Roll, Jesingen, Germany [73] Assignee: Daimler-Benz Aktiengesellschaft,

Stuttgart, Germany 22 Filed: Dec. 22, 1972 21 Appl. No.: 317,780

[30] Foreign Application Priority Data Dec. 23, 1971 Germany 2164357 [52] US. Cl 123/188 S, 29/l56.7 A [51] Int. Cl. FOll 3/22 [58] Field of Search 123/188 S, 193 H;

29/l56.7 R, 156.7 A

[ Mar. 4, 1975 Primary E.\'aminerChar1es J. Myhre Assistant ExaminerW. Rutledge, .lr.

Attorney, Agent, or Firm-Craig & Antotielli [57] ABSTRACT A valve seat ring to be fastened in cylinder heads of internal combustion engines which includes a selftapping thread by means of which the valve seat ring is secured in the material of the cylinder head.

15 Claims, 3 Drawing Figures VALVE SEAT RING FOR THE FASTENING IN CYLINDER HEADS OF INTERNAL COMBUSTION ENGINES The present invention relates to a valve seat ring for purposes of fastening thereof in cylinder heads of internal combustion engines In cylinder heads of internal combustion engines, a

fastening of the valve seat rings takes place, as a rule,

by forcing-in or pressing-in the valve seat ring, which is relatively expensive, but assures on the other hand that a connection between the valve seat rings and the material of the cylinder heads is attained which is favorable as regards the heat transfer. A secure seating of the pressed-in valve seat rings, however, no longer exists with certainty if the internal combustion engine is constructed as high-power internal combustion en gine and the cylinder head is thermally highly loaded or stressed.

The present invention is concerned with the task to provide a fastening which can be established easily, enables a good heat transfer and does not allow a disengagement under thermal load.

The underlying problems are solved according to the present invention in that the valve seat ring is provided with a self-cutting or self-tapping thread.

A valve seat ring provided with a self-tapping or selfcutting thread can be tapped or screwed-in readily in case of cylinder heads made of aluminum or gray cast iron, or also of steel. The heat transfer between a valve seat ring secured and fastened in such a manner and the remaining material of the cylinder head differs only insignificantly from that with a pressed-in or forced-in valve seat ring and at any rate is far more favorable than with a valve seat ring that is inserted with a normal thread.

Furthermore, it is advantageous that a-valve seat ring fastened by means of a self-tapping or self-cutting thread can be exchanged in case of need. Its manufacture is not expensive and the installation not cumbersome.

In one advantageous embodiment of the inventive subject matter, the outer diameter of the self-cutting or self-tapping thread may be constructed tapering conically at the valve seat ring in the screw-in direction in order that during the insertion in the manner of a thread-cutting bolt, at first only very little material is cut away from the cylinder head and a safe guidance is assured.

In order that cut-off chips or shavings do not disturb the installation operation, a groove for chips or shavings may be provided at the valve seat ring which extends in the circumferential direction. Furthermore, several cutting edges extending in the axial direction and interrupting the thread may be provided which enhance the insertion of the valve seat ring and serve as additional chip or shaving grooves.

Finally, for purposes of applying a tool, grooves may be provided at the valve seat ring which are disposed mutually opposite along an inner diameter and extend in the axial direction.

Accordingly, it is an object of the present invention to provide a valve seat ring to be fastened in cylinder heads of internal combustion engines which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a valve seat ring which can be readily installed in cylinder heads of internal combustion engines without cumbersome and expensive operations, yet assures a completely satisfactory heat transfer between the valve seat ring and the material of the cylinder head.

A further object of the present invention resides in a valve seat ring for internal combustion engines which guarantees a completely satisfactory performance even in case of a design of the engine as high power internal combustion engine with thermally very highly loaded cylinder heads.

Another object of the present invention resides in a valve seating ring which enables a fastening thereof in the cylinder head that permits an inexpensive, easy manufacture, a good heat transfer and a possible exchange in case of need.

A further object of the present invention resides in a valve seat ring which assures a proper connection with the cylinder head even when the cylinder head is thermally highly stressed.

These and further objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIG. 1 is a partial cross-sectional view through a cylinder head of an internal combustion engine;

FIG. 2 is an axial cross-sectional view, on an enlarged scale, through a valve seat ring in accordance with the present invention; and

FIG. 3 is an elevational view of the valve seat ring taken in the direction of arrow III of FIG. 2.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, and more particularly to FIG. 1, reference numeral 1 designates in this figure a cylinder head consisting of aluminum, gray cast iron, or steel of an internal combustion engine of otherwise conventional construction. A valve seat ring 4 consisting of hardened steel of any conventional type is arranged in the cylinder head 1 at the orifice of a gas exchange channel 2 at the cylinder head bottom 3 for forming a valve seat for the disk of a valve. The valve seat ring 4 of the present invention is secured by screw-in action by means of a self-cutting or self-tapping thread 5.

As can be seen more clearly from FIGS. 2 and 3, with the valve seat ring 4 of the present invention, the outer diameter of the self-tapping or self-cutting thread 5 is constructed tapering conically in the screw-in direction. A circumferentially extending groove 6 for chips or shavings which is arranged within the area of the forward screw-in end serves for the accommodation of shavings or chips cut away during the screw-in operation from the material of the cylinder head 1. Four cutting edges 7 extending in the axial direction condition the cutting operation. Additionally, the recesses in front of these cutting edges contribute to the removal of the chips or shavings. For the engagement of a tool used for the insertion or possibly also for the disengagement of the valve seat ring 4, grooves 8 are provided which are disposed opposite one another along an inner diameter and extend in the axial direction.

While I have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is sus ceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

What I claim is: a

l. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, the self-cutting thread includes at least one cutting edge which extends in the axial direction of the valve seat ring.

2. A valve seat ring according to claim 1, characterized in that the outer diameter of the self-cutting thread is constructed tapering conically in the screw-in direction.

3. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, the outer diameter of the self-cutting thread is constructed tapering conically in the screw-in direction and in that a groove for shavings is provided in the valve seat ring, which extends in the circumferential direction.

4. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, and characterized in that the outer diameter of the self cutting thread is constructed tapering conically in the screw-in direction, a groove for shavings extending in the circumferential direction is provided in the valve seat ring and in that several cutting edges are provided which extend in the axial direction and interrupt the thread.

5. A valve seat ring according to claim 4, characterized in that grooves are provided for the engagement of a work tool which are disposed mutually opposite along an inner diameter and extend essentially in the axial direction.

6. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, and in that a groove for shavings is provided in the valve seat ring, which extends in the circumferential direction.

7. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of self-cutting thread at the valve seat ring, and characterized in that several cutting edges are pro vided which extend in the axial direction and interrupt the thread.

8. A valve seat ring according to claim 1, characterized in that grooves are provided for the engagement of a work tool which are disposed mutually opposite along an inner diameter and extend essentially in the axial direction.

9. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, and characterized in that a groove for shavings is provided in the valve seat ring, which extends in the circumferential direction, and in that several cutting edges are provided which extend in the axial direction and interrupt the thread.

10. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, a groove for shavings is provided in the valve seat ring, which extends in the circumferential direction, and in that grooves are provided for the engagement of a work tool which are disposed mutually opposite along an inner diameter and which extend essentially in the axial direction.

11. In combination with a cylinder head, a valve seat arrangement for an internal combustion engine, the valve seat arrangement comprising: a valve seat ring, a bore means provided in the cylinder head for receiving said'valve seat ring, said bore means including a smooth peripheral wall portion, and self-cutting thread means provided on said valve seat ring for threadably fastening said valve seat ring in said smooth peripheral wall portion of said bore means, said self'cutting thread means including at least one cutting edge extending in the axial direction of the valve seat ring.

12. In combination with a cylinder head, a valve seat arrangement for an internal combustion engine, the valve seat arrangement comprising: a valve seat ring means, a bore means provided in the cylinder head for receiving said valve seat ring, said bore means including a smooth peripheral wall portion, self-cutting thread means provided on said valve seat ring for threadably fastening said valve seat ring in said smooth peripheral wall portion of said bore means, and additional cutting means provided on said valve seat ring for conditioning said bore means for said self-cutting thread means.

13. The combination according to claim 12, wherein means are provided in said valve seat ring for receiving material removed from said wall portion when said valve seat ring is inserted.

14. The combination according to claim 13, wherein means are provided for facilitating insertion and removal of said valve seat ring from said bore means.

15. The combination according to claim 11, wherein said self-cutting thread means tapers conically in the direction of insertion of said valve seat ring into said bore means. 

1. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a selfcutting thread at the valve seat ring, the self-cutting thread includes at least one cutting edge which extends in the axial direction of the valve seat ring.
 2. A valve seat ring according to claim 1, charActerized in that the outer diameter of the self-cutting thread is constructed tapering conically in the screw-in direction.
 3. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, the outer diameter of the self-cutting thread is constructed tapering conically in the screw-in direction and in that a groove for shavings is provided in the valve seat ring, which extends in the circumferential direction.
 4. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, and characterized in that the outer diameter of the self-cutting thread is constructed tapering conically in the screw-in direction, a groove for shavings extending in the circumferential direction is provided in the valve seat ring and in that several cutting edges are provided which extend in the axial direction and interrupt the thread.
 5. A valve seat ring according to claim 4, characterized in that grooves are provided for the engagement of a work tool which are disposed mutually opposite along an inner diameter and extend essentially in the axial direction.
 6. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a selfcutting thread at the valve seat ring, and in that a groove for shavings is provided in the valve seat ring, which extends in the circumferential direction.
 7. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of self-cutting thread at the valve seat ring, and characterized in that several cutting edges are provided which extend in the axial direction and interrupt the thread.
 8. A valve seat ring according to claim 1, characterized in that grooves are provided for the engagement of a work tool which are disposed mutually opposite along an inner diameter and extend essentially in the axial direction.
 9. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, and characterized in that a groove for shavings is provided in the valve seat ring, which extends in the circumferential direction, and in that several cutting edges are provided which extend in the axial direction and interrupt the thread.
 10. A valve seat ring for fastening in cylinder heads of internal combustion engines, characterized by the arrangement of a self-cutting thread at the valve seat ring, a groove for shavings is provided in the valve seat ring, which extends in the circumferential direction, and in that grooves are provided for the engagement of a work tool which are disposed mutually opposite along an inner diameter and which extend essentially in the axial direction.
 11. In combination with a cylinder head, a valve seat arrangement for an internal combustion engine, the valve seat arrangement comprising: a valve seat ring, a bore means provided in the cylinder head for receiving said valve seat ring, said bore means including a smooth peripheral wall portion, and self-cutting thread means provided on said valve seat ring for threadably fastening said valve seat ring in said smooth peripheral wall portion of said bore means, said self-cutting thread means including at least one cutting edge extending in the axial direction of the valve seat ring.
 12. In combination with a cylinder head, a valve seat arrangement for an internal combustion engine, the valve seat arrangement comprising: a valve seat ring means, a bore means provided in the cylinder head for receiving said valve seat ring, said bore means including a smooth peripheral wall portion, self-cutting thread means provided on said valve seat ring for threadably fastening said valve seat ring in said smooth peripheral wall portion of said bore means, and additional cutting meaNs provided on said valve seat ring for conditioning said bore means for said self-cutting thread means.
 13. The combination according to claim 12, wherein means are provided in said valve seat ring for receiving material removed from said wall portion when said valve seat ring is inserted.
 14. The combination according to claim 13, wherein means are provided for facilitating insertion and removal of said valve seat ring from said bore means.
 15. The combination according to claim 11, wherein said self-cutting thread means tapers conically in the direction of insertion of said valve seat ring into said bore means. 